RADNOR, Pa. (CBS) — A Virginia man has been sentenced to at least 15 years in a Pennsylvania prison after admitting to having sex with a 13-year-old girl from Radnor whom he met online late in 2012.

Delaware County District Attorney Jack Whelan says 20-year-old Ashley Hareford chatted up the young girl, and they agreed to meet (Read Related Story).

“He came from Virginia,” Whelan says, “came to her house in Radnor and then ultimately had a sexual encounter with her.”

A few days later, they boarded a bus in Philadelphia, but never got to Hareford’s home in the western part of Virginia. Police used Hareford’s cell phone to track him and the girl down to the Washington D.C. bus station.

Whelan says authorities in Washington state are looking at Hareford in a case involving a 14-year-old that closely resembles this one.

Hareford’s guilty plea will also make him a Megan’s Law violator for life.